he joked about his predecessor, hillary clinton, saying he had big heels to fill. >>> public records indicate superdome officials were worried about a possible blackout months before the super bowl. officials still aren't sure what caused the 34-minute blackout. according to the "new orleans times picayune," they're looking at equipment that controls the flow of electricity from the power company to the stadium. now it was part of a recent multimillion dollar upgrade. armen ketayan was there. >> reporter: the root cause remains under investigation. the superdome executive doug thornton said it was a shutdown to one of the main lines powering the dome. >> all we know is we had an interruption in service. >> reporter: he said power to the company was fed into a substation which split the electrical feed into two lines running power to the stadium. it was the main a line, he said, that went dark without warning. >> sensed abnormalities in their substation. and it -- it shunted the power to the superdome. >> reporter: it happened some 90 seconds into the third quarter, and we were in the